April^ 1836. fields of dead coral. 



549 



the level of the lagoon. Now it acts in a directly contrary 

 manner ; for the water^ not only is not increased by currents 

 from the outside, but is blown outwards by the force of the 

 wind. Hence, it is observed, that the tides near the head 

 of the lagoon do not rise so high during strong breezes as 

 on ordinary occasions. This difference of level, although no 

 doubt very small, has I believe caused the death of those 

 coral groves, which under the former condition of things 

 had attained the utmost possible limit of upward growth. 



A few miles north of Keeling there is another small 

 lagoon island, the centre of which is nearly filled up. Cap- 

 tain Ross found in the conglomerate of the outer coast a 

 well rounded fragment of greenstone, rather larger than a 

 man^s head ; he and the men with him were so much sur- 

 prised at this, that they brought it away and preserved it 

 as a curiosity. The occurrence of this one stone, where 

 every other particle of matter is calcareous, certainly is very 

 puzzling. The island has scarcely ever been visited, nor is 

 it probable that a ship had been wrecked there. From the 

 absence of any better explanation, I came to the conclu- 

 sion that it must have come there entangled in the roots of 

 some large tree : when, however, I considered the great 

 distance from the nearest land, the combination of chances 

 against a stone thus being entangled, the tree washed into 

 the sea, floated so far, then landed safely, and the stone 

 finally so embedded as to allow of its discovery, I was almost 

 ashamed of imagining a means of transport so improbable. 

 It was therefore with great interest that I found Chamisso,^ 

 the justly distinguished naturalist who accompanied Kot- 

 zebue, stating that the inhabitants of the Radack Archipelago, 



* Kotzebue's first voyage, vol. iii., p. 155. It is said, *' The sea throws 

 up on the reefs of Radack the trunks of northern firs (!) and trees of the 

 torrid zone (palms, bamboos). It provides the inhabitants not only with 

 timber for boats, but it also brings them in wrecks of European ships, the 

 iron which they want." — " They receive, in a similar manner, another 

 treasure, hard stones^ fit for whetting. They are sought for in the roots 

 and hollows of the trees wliich tlie sea throws up." 



